Electronic device

Abstract

To provide an electronic device capable of effectively utilizing dead space occurring when electronic components with different heights are placed on a substrate.SOLUTION: An electronic device of the present invention includes: a base member; a plurality of first support columns placed on the base member; a first substrate supported by the first support columns above the base member; at least one first electronic component placed on the first substrate; a plurality of second support columns placed on the first substrate; a second substrate supported by the second support columns above the first substrate; and at least one second electronic component placed on the second substrate. The height of the first electronic component is higher than that of the second electronic component, the second substrate is placed above the first substrate so as not to overlap the first electronic component in plain view, and the top edge of the tallest second electronic component on the second substrate is positioned lower than the top edge of the tallest first electronic component.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electronic device. [Background technology]

[0002] Patent Document 1 discloses an inverter device provided with a semiconductor module, a smoothing capacitor, and a discharge resistor. In this inverter device, the discharge resistor is arranged to protrude in the height direction in order to reduce the size in a plan view. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 67132463 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the inverter device described above, because only the discharge resistors protrude in the height direction, there is a problem of dead space in the height direction in areas other than the discharge resistors. This problem is not limited to cases where only the discharge resistors are provided protruding in the height direction, but can occur in any device in which electronic components of different heights are arranged on a board. The present invention has been made to solve the above problem, and it is an object of the present invention to provide an electronic device that can effectively utilize the dead space that occurs when electronic components of different heights are arranged on a board. [Means for solving the problem]

[0005] The electronic device of the present invention comprises a base member, a plurality of first supports arranged on the base member, a first board supported by the first supports above the base member, at least one first electronic component arranged on the first board, a plurality of second supports arranged on the first board, a second board supported by the second supports above the first board, and at least one second electronic component arranged on the second board, wherein the height of the first electronic component is greater than that of the second electronic component, the second board is arranged above the first board so as not to overlap with the first electronic component in a planar view, and the upper end of the highest second electronic component arranged on the second board is arranged at a lower position than the upper end of the highest first electronic component. [Effects of the Invention]

[0006] According to the electronic device of the present invention, it is possible to effectively utilize the dead space that occurs when electronic components having different heights are arranged on a board. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a circuit diagram of a drive system of an electric vehicle to which an inverter device, which is an embodiment of an electronic device according to the present invention, is applied; [Figure 2] FIG. 2 is a plan view of the inverter device. [Figure 3] FIG. 2 is a plan view of a drive circuit board. [Figure 4] FIG. 4 is a cross-sectional view of FIG. [Figure 5] FIG. 2 is a plan view of a second substrate. [Figure 6] FIG. 2 is a bottom view of the second substrate. [Figure 7] FIG. 10 is a cross-sectional view showing another example of a drive circuit board. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment in which an electronic device according to the present invention is applied to a power conversion device will be described with reference to the drawings. More specifically, this power conversion device is applied to an inverter device (an example of a power conversion device) of a motor generator mounted in an electric vehicle (an example of an electrically powered vehicle) as a driving source for traveling. Below, first, the circuit configuration of the drive system of the electric vehicle will be described, and then the drive circuit board of the inverter device will be described.

[0009] <1. Circuit configuration of electric vehicle drive system> 1 is a circuit diagram of a drive system for an electric vehicle to which an inverter device according to this embodiment is applied. The drive system 1 includes a DC power supply 2 (high-power battery), an inverter device 3, and a motor generator 11.

[0010] The DC power supply 2 is a high-voltage battery for driving an electric vehicle, and includes a battery (not shown) in which multiple secondary batteries are connected in series or parallel. The DC power supply 2 outputs a DC voltage between the P bus bar 12 (positive) and the N bus bar 13 (negative).

[0011] The inverter device 3 converts DC power supplied from the DC power supply 2 into AC power and outputs the converted power to the motor generator 11. The inverter device 3 also converts AC power generated by the motor generator 11 into DC power and outputs the converted power to the DC power supply 2. The inverter device 3 includes a power module 4 (power conversion module), a smoothing capacitor 5, a discharge resistor unit 6, and a three-phase line 7.

[0012] The power module 4 has a plurality of switch groups on a substrate, each of which is made up of a plurality of modularized switching elements 4a, such as IGBTs (Insulated Gate Bipolar Transistors) or MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). The power module 4 converts DC power from the DC power supply 2 by turning the switching elements on and off based on control signals from a controller mounted on a drive circuit board (described later), and outputs AC power to the motor generator 11 through the three-phase line 7. The power module 4 also converts regenerative power (AC power) of the motor generator 11 into DC power through the regenerative operation of the motor generator 11, which is then supplied to the DC power supply 2, and the DC power supply 2 is charged by the regenerative power of the motor generator 11.

[0013] A motor generator 11 is electrically connected to the AC side of the power module 4 via a three-phase line 7. A smoothing capacitor 5 is electrically connected to the DC side of the power module 4. The power module 4 has a plurality of switching elements 4a and a plurality of diodes 4b. A transistor such as an IGBT or a MOSFET is used for the switching element 4a. The diode 4b is a reflux diode. The switching elements 4a and the diodes 4b are connected in parallel with their current conduction directions opposite to each other. A circuit in which multiple parallel circuits of switching elements 4a and diodes 4b are connected in series forms the arm circuits 40U, 40V, and 40W (power conversion circuits) of the U, V, and W phases. The multiple arm circuits 40U, 40V, and 40W are connected in parallel between the P bus bar 12 and the N bus bar 13.

[0014] Smoothing capacitor 5 has the function of smoothing voltage fluctuations. Smoothing capacitor 5 stores electricity when the voltage is high and discharges when the voltage is low, suppressing voltage fluctuations. In other words, smoothing capacitor 5 smoothes the input and output voltages on the DC side of each of arm circuits 40U, 40V, and 40W of the U, V, and W phases. Smoothing capacitor 5 is connected between P bus bar 12 and N bus bar 13.

[0015] Discharge resistor unit 6 discharges the charge accumulated in smoothing capacitor 5 when inverter device 3 stops operating. Discharge resistor unit 6 is connected between P bus bar 12 and N bus bar 13.

[0016] Three-phase line 7 includes conductive bus bars 7U, 7V, and 7W for U, V, and W phases, respectively. U, V, and W phase bus bars 7U, 7V, and 7W electrically connect terminals of U, V, and W phase arm circuits 40U, 40V, and 40W to terminals of the motor generator 11 for each phase.

[0017] The motor generator 11 is, for example, a synchronous motor with a permanent magnet embedded in the rotor and a stator coil wound around the stator. The motor generator 11 is connected to the axle of the vehicle and operates electromagnetically using power supplied from the inverter device 3 to generate rotational force.

[0018] <2. Configuration of the drive circuit board> Fig. 2 is a plan view of the inverter device. As shown in Fig. 2, the inverter device 3 includes a base member 10, on which the above-described power module 4, smoothing capacitor 5, and drive circuit board 8 are arranged. The above-described discharge resistor unit 6 is also provided on the drive circuit board 8. A controller provided on the drive circuit board 8 controls the on / off of the switching element 4a of the power module 4. The drive circuit board 8 will be described in detail below.

[0019] FIG. 3 is a plan view of the drive circuit board, and FIG. 4 is a cross-sectional view of FIG. 3. As shown in FIGS. 3 and 4, the drive circuit board 8 includes a first substrate 81 and a second substrate 82. The first substrate 81 is formed in a rectangular shape and is supported by a plurality of support posts 83 (four in this embodiment) provided on a base member 10. That is, the first substrate 81 is disposed above the base member 10 with gaps therebetween. The plurality of support posts 83 are formed of a conductive material such as metal and are connected to the four corners of the first substrate 81. Two of the plurality of support posts 83 extend upward through the first substrate 81 and support the second substrate 82 above the first substrate 81. As a result, electronic components on the second substrate 82, which will be described later, are electrically connected to the electronic components and wiring pattern of the first substrate 81 via the support posts 83.

[0020] The base member 10 is made of an insulating material such as a resin material. Furthermore, a coolant passage 101 through which a coolant passes is formed inside the base member 10 where the drive circuit board 8 is disposed. The lower end of each support pillar 83 is connected to a conductive base 84 embedded in the base member 10. A plurality of protrusions 841 are formed on the lower surface of each base 84, and each protrusion 841 is inserted into a recess formed near the coolant passage 101. As a result, the protrusions 841, base 84, and support pillars 83 are cooled by the coolant.

[0021] The first substrate 81 is made of an insulating material and has a rectangular shape, and has a wiring pattern and a plurality of electronic components mounted on its upper surface. However, for ease of explanation, only some of the electronic components are shown in Figures 3 and 4. The electronic components mounted on the first substrate 81 include, for example, a controller (not shown) that turns on and off the switching element 4a of the power module 4, a transformer 91, and a connector 92. Of these, the connector 92 can be connected to a cable for connection to the smoothing capacitor 5, and is provided with a P terminal and an N terminal.

[0022] The transformer 91 and the connector 92 are examples of tall electronic components, and such tall electronic components are mounted on the first substrate 81.

[0023] Although the power module 4 is omitted in FIGS. 3 and 4, the power module 4 can be disposed between the first substrate 81 and the base member 10, for example.

[0024] Next, the second substrate 82 will be described with reference to FIGS. 5 and 6. FIG. 5 is a plan view of the second substrate, and FIG. 6 is a bottom view of the second substrate. As shown in FIG. 5, the second substrate 82 is made of an insulating material and is formed in a narrow rectangular shape so as to extend along one side (the lower side in FIG. 3) of the first substrate 81. The second substrate 82 is disposed in a position so as not to overlap the tall electronic components 91, 92 of the first substrate 81 in a plan view. A plurality of first wiring patterns 62 are disposed at predetermined intervals on the upper surface of the second substrate 82. A plurality of second wiring patterns 63 are disposed at predetermined intervals on the lower surface of the second substrate 82 so as to correspond to the first wiring patterns 62 on the upper surface. The first wiring patterns 62 and the second wiring patterns 63 are electrically connected via via holes formed in the second substrate 82. Two of the four supports 83 described above are electrically connected to the wiring patterns 62, 63 at both ends of the second substrate 82. Each support post 83 is connected to the P terminal and N terminal of the connector 92 described above on the first substrate 81 via a wiring pattern.

[0025] A plurality of discharge resistors 61 are provided on the upper surface of the second substrate 82 so as to straddle adjacent first wiring patterns 62. Therefore, the plurality of discharge resistors 61 are connected in series via the wiring patterns 62, 63. As a result, the serially connected discharge resistors 61 are connected to the P terminal and the N terminal of the connector 92 via the support posts 83.

[0026] The second substrate 82 configured as above constitutes the above-mentioned discharge resistor unit 6. In this embodiment, as shown in Fig. 4, the electronic components on the second substrate 82 are configured to be arranged at a position where the upper end L2 thereof is lower than the upper end L1 of the tallest electronic component (connector 92) on the first substrate 81. To achieve this positional relationship, a tall electronic component (first electronic component) such as the connector 92 is arranged on the first substrate 81, and a short electronic component (second electronic component) such as the discharge resistor 61 is arranged on the second substrate 82.

[0027] <3. Features> In this embodiment, the following effects can be obtained. (1) When a tall electronic component such as connector 92 is arranged on first substrate 81, the space between first substrate 81 and the upper end of connector 92 becomes dead space in the area of ​​first substrate 81 where connector 92 is not arranged. Therefore, in this embodiment, second substrate 82 is arranged above first substrate 81 in this dead space, and a short electronic component such as discharge resistor 61 is arranged therein. Therefore, the dead space can be effectively utilized. Furthermore, since space for arranging discharge resistor 61 is not required on first substrate 81, first substrate 81 can be made smaller in the planar direction.

[0028] (2) By arranging the discharge resistor 61, which is prone to generating heat, on the second substrate 82, the discharge resistor 61 can be separated from electronic components (such as electrolytic capacitors) which are arranged on the first substrate 81 and have low heat resistance.

[0029] (3) Because the support posts 83 connecting the first substrate 81 and the second substrate 82 are formed of a conductive material, the discharge resistor 61 of the second substrate 82 can be electrically connected to the electronic components and wiring pattern of the first substrate 81 via the support posts 83. Therefore, the discharge resistor 61 can be electrically connected to the P terminal and the N terminal of the connector 92 of the first substrate 81, and the discharge resistor 61 and the smoothing capacitor 5 can be electrically connected.

[0030] (4) The support pillars 83 are connected to the first substrate 81 and the second substrate 82 and extend to the vicinity of the coolant path 101, so that the first substrate 81 and the second substrate 82 can be cooled via the support pillars 83. In particular, the discharge resistor 61 has the function of discharging the charge accumulated in the smoothing capacitor 5, and generates heat during discharge. Therefore, the support pillars 83 can effectively cool the heated discharge resistor 61.

[0031] (5) The second wiring pattern 63 is disposed on the lower surface of the second substrate 82, and is electrically connected to the first wiring pattern 62 on the upper surface. In addition, the second substrate 82 is disposed above the first substrate 81, and a space is formed below the second substrate 82. Therefore, the second wiring pattern 63 exposed on the lower surface of the second substrate 82 can be cooled by air, and thereby the discharge resistor 61 can be cooled.

[0032] <4. Modifications> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, the following modifications are possible. Furthermore, the gist of the following modifications can be appropriately combined with each other and can also be combined with the above embodiment.

[0033] (1) In the above embodiment, the transformer 91 and the connector 92 are arranged on the first substrate 81 as examples of tall electronic components, and the discharge resistor 61 is arranged on the second substrate 82 as an example of a short electronic component. However, the electronic components to be arranged are not limited to these, and various modifications are possible. That is, it is sufficient that the top end of the tallest electronic component arranged on the second substrate 82 is lower than the top end of the tallest electronic component arranged on the first substrate 81, and the heights of the tall electronic components, the short electronic components, and the second substrate 82 are selected so as to satisfy this positional relationship. In addition to the discharge resistor 61 described above, the electronic components arranged on the second substrate 82 can also be, for example, chip resistors, chip capacitors, etc.

[0034] (2) As a structure for cooling the discharge resistor 61, for example, an additional support pillar 85 can be provided as shown in FIG. 7. This support pillar 85 extends from near the center of the second substrate 82, penetrating the first substrate 81, and to the base member 10. However, this support pillar 85 is not electrically connected to the first substrate 81. Furthermore, like the other support pillars 83, a base 84 and a protrusion 841 are provided at the lower end of this support pillar 85, and are cooled by the refrigerant. Therefore, the second substrate 82 can be further cooled by this support pillar 85. The number and positions of such additional support pillars 85 are not particularly limited.

[0035] (3) In the above embodiment, the first substrate 81 and the second substrate 82 are connected via the support pillars 83, but the support pillars (first support pillars) connecting the base member 10 and the first substrate 81 and the support pillars (second support pillars) connecting the first substrate 81 and the second substrate 82 can also be formed of separate members. This allows the number and positions of the first support pillars and the second support pillars to be different.

[0036] However, since the second substrate 82 only needs to be placed in a position where it does not overlap with tall electronic components, for example, on the first substrate 81, short electronic components can also be placed below the second substrate 82.

[0037] (4) The position, shape, and structure of the second substrate 82 are not particularly limited, as long as they satisfy the above-described positional relationship and are disposed in a position that does not overlap with tall electronic components on the first substrate 81. Furthermore, the wiring patterns 62, 63 of the second substrate 82 can be changed as appropriate; for example, the second wiring pattern 63 on the underside is not necessarily required and may be provided as needed.

[0038] (5) In the above embodiment, the electronic device of the present invention is applied to an inverter device, but the present invention is not limited to this and can be applied to various electronic devices. In other words, the present invention can be applied to electronic devices in which the above-mentioned dead space may occur when tall electronic components are mounted on a board. [Explanation of symbols]

[0039] 3: Inverter device 8: Drive circuit board 10: Base material 61: Discharge resistor (second electronic component) 62: First wiring pattern 63: Second wiring pattern 81: First board 82: Second board 83: Support (1st support, 2nd support) 91: Transformer (first electronic component) 92: Connector (first electronic component) 101: refrigerant path

Claims

1. A base member; a plurality of first support posts disposed on the base member; the first substrate supported by the first support column above the base member; at least one first electronic component disposed on the first substrate; a plurality of second support pillars disposed on the first substrate; a second substrate supported by the second support column above the first substrate; at least one second electronic component disposed on the second substrate; Equipped with The height of the first electronic component is greater than that of the second electronic component, the second substrate is disposed above the first substrate so as not to overlap with the first electronic component in a plan view; The upper end of the second electronic component that is the highest is arranged on the second substrate at a position lower than the upper end of the first electronic component that is the highest. electronic equipment.

2. the first board is a drive circuit board for an inverter device that drives a motor, the first electronic component includes at least one of a transformer and a connector that electrically connects the first substrate and another electronic component; the second electronic component is a discharge resistor; The electronic device according to claim 1 .

3. a connector having a P terminal and an N terminal is disposed on the first substrate; the second support pillar is electrically conductive; the second electronic component on the second substrate is electrically connected to a P terminal and an N terminal of the connector via the second support pillar; The electronic device according to claim 2 .

4. the base member includes a coolant passage through which a coolant flows; an end of the first support column on the base member side is configured to be cooled by the refrigerant, the second substrate is configured to be cooled by the refrigerant via the first support columns and the second support columns.

3. The electronic device according to claim 1 or 2.

5. a first wiring pattern is disposed on an upper surface of the second substrate; a second wiring pattern electrically connected to the first wiring pattern is disposed on the lower surface of the second substrate; The second electronic component is connected to the first wiring pattern.

3. The electronic device according to claim 1 or 2.

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